[Qgis-user] NTV2 Grid Shits

[stevejking]

Tyler,
I think the following might work.

Pick up the NAD27toATS77 and ATS77toNAD83 here:
http://georepository.com/search/by-name/query/Ats77/transformation_page/1/#transformation

Add the two multiband grids together somehow (open gsb's as raster in qgis)
i.e. Band 1 longitude shift and band 2 latitude shift. The other two bands
can be zero. Save the new grid as a multi band geotif.

>From a command prompt Navigate to gdal_translate located in QGIS 2.16\Bin\
or equivalent
Then type:
gdal_translate <path\multibandgeo.tif> -of NTV2 <path\new_ntv2_grid.gsb>

This will create new_ntv2_grid.gsb which will be NAD27toNAD83 ( a proxy for
wgs84 as far as proj4 is concerned).

Just remember to put the gsb on your from string, and your to string
+towgs84=0,0,0,0,0,0,0



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